Arroyo (8-7) allowed three hits, including Brian McCann’s two-out solo homer in the seventh, and walked one. Sam LeCure pitched a perfect eighth and Aroldis Chapman gave up a run in the ninth before earning his 21st save.
Braves outfielders B.J. Upton and Justin Upton left the game with injuries. Jason Heyward was held out one day after he strained his right hamstring.
B.J. Upton strained his right adductor muscle in the first inning. Justin Upton strained his left calf while running to first base in the seventh.
The Braves’ patchwork outfield at the end of the game included Tyler Pastornicky, Reed Johnson and rookie Joey Terdoslavich.
Pastornicky walked with two outs in the ninth and went to second on defensive indifference. He scored on Freddie Freeman’s single, but McCann popped out to end the game.
The Reds jumped on Kris Medlen (6-9) right at the start. Shin-Soo Choo singled and moved to second on Derrick Robinson’s bunt single. Medlen walked Joey Votto to set up Phillips’ two-run single to center. Votto scored on Todd Frazier’s triple off B.J. Upton’s glove and left knee.
Upton’s right knee dug into the grass as he attempted to make the catch. He appeared to favor his right side as he walked slowly off the field, accompanied by assistant trainer Jim Lovell.
It was another big blow in a series of injuries for the Braves’ outfield.
General manager Frank Wren announced during the game that Jordan Schafer’s right ankle injury is more serious than originally believed. Schafer went on the 15-day disabled list on July 4 with what was called an ankle contusion, but a MRI on Friday revealed a stress fracture. Wren said the normal recovery period for the injury is six weeks “and he’s two to three weeks into it.”
Evan Gattis, who has made 11 starts in left field, could return from an oblique injury after the All-Star break.
The Reds chased Medlen in the fifth. Robinson singled and moved to third on Votto’s double before Medlen hit Phillips with a pitch to load the bases. Left-hander Alex Wood then came in and gave up a sacrifice fly to Jay Bruce.
Medlen was charged with four runs and nine hits. Medlen, who was 4-1 with a 2.14 ERA in five June starts, has allowed a combined 10 runs in two straight losses.
The Braves had only two hits before McCann’s seventh-inning homer. Medlen singled with two out in the third and Justin Upton singled to right field in the fourth. Upton was thrown out at second by Bruce.
NOTES: Reds LHP Sean Marshall threw to batters before the game. Manager Dusty Baker said Marshall is closer to returning from his second DL stint with a sore left shoulder. ... RHP Homer Bailey will make his second start since throwing his second career no-hitter against San Francisco on July 2 when he faces Atlanta’s Mike Minor today. Bailey followed the no-hitter with a loss at Milwaukee on Monday.